source4/libcli/finddcs_cldap.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    a composite API for finding a DC and its name via CLDAP
   5
   6    Copyright (C) Andrew Tridgell 2010
   7    Copyright (C) Andrew Bartlett 2010
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21 */
  22
  23 #include "include/includes.h"
  24 #include <tevent.h>
  25 #include "libcli/resolve/resolve.h"
  26 #include "libcli/cldap/cldap.h"
  27 #include "libcli/finddc.h"
  28 #include "libcli/security/security.h"
  29 #include "lib/util/tevent_ntstatus.h"
  30 #include "lib/tsocket/tsocket.h"
  31 #include "libcli/composite/composite.h"
  32
  33 struct finddcs_cldap_state {
  34         struct tevent_context *ev;
  35         struct tevent_req *req;
  36         const char *domain_name;
  37         struct dom_sid *domain_sid;
  38         const char *srv_name;
  39         const char **srv_addresses;
  40         uint32_t minimum_dc_flags;
  41         uint32_t srv_address_index;
  42         struct cldap_socket *cldap;
  43         struct cldap_netlogon *netlogon;
  44 };
  45
  46 static void finddcs_cldap_srv_resolved(struct composite_context *ctx);
  47 static void finddcs_cldap_netlogon_replied(struct tevent_req *req);
  48 static bool finddcs_cldap_srv_lookup(struct finddcs_cldap_state *state,
  49                                      struct finddcs *io,
  50                                      struct resolve_context *resolve_ctx,
  51                                      struct tevent_context *event_ctx);
  52 static bool finddcs_cldap_nbt_lookup(struct finddcs_cldap_state *state,
  53                                      struct finddcs *io,
  54                                      struct resolve_context *resolve_ctx,
  55                                      struct tevent_context *event_ctx);
  56 static void finddcs_cldap_name_resolved(struct composite_context *ctx);
  57 static void finddcs_cldap_next_server(struct finddcs_cldap_state *state);
  58 static bool finddcs_cldap_ipaddress(struct finddcs_cldap_state *state, struct finddcs *io);
  59
  60
  61 /*
  62  * find a list of DCs via DNS/CLDAP
  63  */
  64 struct tevent_req *finddcs_cldap_send(TALLOC_CTX *mem_ctx,
  65                                       struct finddcs *io,
  66                                       struct resolve_context *resolve_ctx,
  67                                       struct tevent_context *event_ctx)
  68 {
  69         struct finddcs_cldap_state *state;
  70         struct tevent_req *req;
  71
  72         req = tevent_req_create(mem_ctx, &state, struct finddcs_cldap_state);
  73         if (req == NULL) {
  74                 return NULL;
  75         }
  76
  77         state->req = req;
  78         state->ev = event_ctx;
  79         state->minimum_dc_flags = io->in.minimum_dc_flags;
  80
  81         if (io->in.domain_name) {
  82                 state->domain_name = talloc_strdup(state, io->in.domain_name);
  83                 if (tevent_req_nomem(state->domain_name, req)) {
  84                         return tevent_req_post(req, event_ctx);
  85                 }
  86         } else {
  87                 state->domain_name = NULL;
  88         }
  89
  90         if (io->in.domain_sid) {
  91                 state->domain_sid = dom_sid_dup(state, io->in.domain_sid);
  92                 if (tevent_req_nomem(state->domain_sid, req)) {
  93                         return tevent_req_post(req, event_ctx);
  94                 }
  95         } else {
  96                 state->domain_sid = NULL;
  97         }
  98
  99         if (io->in.server_address) {
 100                 DEBUG(4,("finddcs: searching for a DC by IP %s\n", io->in.server_address));
 101                 if (!finddcs_cldap_ipaddress(state, io)) {
 102                         return tevent_req_post(req, event_ctx);
 103                 }
 104         } else if (io->in.domain_name) {
 105                 if (strchr(state->domain_name, '.')) {
 106                         /* looks like a DNS name */
 107                         DEBUG(4,("finddcs: searching for a DC by DNS domain %s\n", state->domain_name));
 108                         if (!finddcs_cldap_srv_lookup(state, io, resolve_ctx,
 109                                                       event_ctx)) {
 110                                 return tevent_req_post(req, event_ctx);
 111                         }
 112                 } else {
 113                         DEBUG(4,("finddcs: searching for a DC by NBT lookup %s\n", state->domain_name));
 114                         if (!finddcs_cldap_nbt_lookup(state, io, resolve_ctx,
 115                                                       event_ctx)) {
 116                                 return tevent_req_post(req, event_ctx);
 117                         }
 118                 }
 119         } else {
 120                 /* either we have the domain name or the IP address */
 121                 tevent_req_nterror(req, NT_STATUS_INVALID_PARAMETER_MIX);
 122                 DEBUG(2,("finddcs: Please specify at least the domain name or the IP address! \n"));
 123                 return tevent_req_post(req, event_ctx);
 124         }
 125
 126         return req;
 127 }
 128
 129
 130 /*
 131   we've been told the IP of the server, bypass name
 132   resolution and go straight to CLDAP
 133 */
 134 static bool finddcs_cldap_ipaddress(struct finddcs_cldap_state *state, struct finddcs *io)
 135 {
 136         NTSTATUS status;
 137
 138         state->srv_addresses = talloc_array(state, const char *, 2);
 139         if (tevent_req_nomem(state->srv_addresses, state->req)) {
 140                 return false;
 141         }
 142         state->srv_addresses[0] = talloc_strdup(state->srv_addresses, io->in.server_address);
 143         if (tevent_req_nomem(state->srv_addresses[0], state->req)) {
 144                 return false;
 145         }
 146         state->srv_addresses[1] = NULL;
 147         state->srv_address_index = 0;
 148
 149         finddcs_cldap_next_server(state);
 150         return tevent_req_is_nterror(state->req, &status);
 151 }
 152
 153 /*
 154   start a SRV DNS lookup
 155  */
 156 static bool finddcs_cldap_srv_lookup(struct finddcs_cldap_state *state,
 157                                      struct finddcs *io,
 158                                      struct resolve_context *resolve_ctx,
 159                                      struct tevent_context *event_ctx)
 160 {
 161         struct composite_context *creq;
 162         struct nbt_name name;
 163
 164         if (io->in.site_name) {
 165                 state->srv_name = talloc_asprintf(state, "_ldap._tcp.%s._sites.%s",
 166                                            io->in.site_name, io->in.domain_name);
 167         } else {
 168                 state->srv_name = talloc_asprintf(state, "_ldap._tcp.%s", io->in.domain_name);
 169         }
 170
 171         DEBUG(4,("finddcs: looking for SRV records for %s\n", state->srv_name));
 172
 173         make_nbt_name(&name, state->srv_name, 0);
 174
 175         creq = resolve_name_ex_send(resolve_ctx, state,
 176                                     RESOLVE_NAME_FLAG_FORCE_DNS | RESOLVE_NAME_FLAG_DNS_SRV,
 177                                     0, &name, event_ctx);
 178         if (tevent_req_nomem(creq, state->req)) {
 179                 return false;
 180         }
 181         creq->async.fn = finddcs_cldap_srv_resolved;
 182         creq->async.private_data = state;
 183
 184         return true;
 185 }
 186
 187 /*
 188   start a NBT name lookup for domain<1C>
 189  */
 190 static bool finddcs_cldap_nbt_lookup(struct finddcs_cldap_state *state,
 191                                      struct finddcs *io,
 192                                      struct resolve_context *resolve_ctx,
 193                                      struct tevent_context *event_ctx)
 194 {
 195         struct composite_context *creq;
 196         struct nbt_name name;
 197
 198         make_nbt_name(&name, state->domain_name, NBT_NAME_LOGON);
 199         creq = resolve_name_send(resolve_ctx, state, &name, event_ctx);
 200         if (tevent_req_nomem(creq, state->req)) {
 201                 return false;
 202         }
 203         creq->async.fn = finddcs_cldap_name_resolved;
 204         creq->async.private_data = state;
 205         return true;
 206 }
 207
 208 /*
 209   fire off a CLDAP query to the next server
 210  */
 211 static void finddcs_cldap_next_server(struct finddcs_cldap_state *state)
 212 {
 213         struct tevent_req *subreq;
 214         struct tsocket_address *dest;
 215         int ret;
 216         NTSTATUS status;
 217
 218         if (state->srv_addresses[state->srv_address_index] == NULL) {
 219                 tevent_req_nterror(state->req, NT_STATUS_OBJECT_NAME_NOT_FOUND);
 220                 DEBUG(2,("finddcs: No matching CLDAP server found\n"));
 221                 return;
 222         }
 223
 224         /* we should get the port from the SRV response */
 225         ret = tsocket_address_inet_from_strings(state, "ip",
 226                                                 state->srv_addresses[state->srv_address_index],
 227                                                 389,
 228                                                 &dest);
 229         if (ret == 0) {
 230                 status = NT_STATUS_OK;
 231         } else {
 232                 status = map_nt_error_from_unix_common(errno);
 233         }
 234         if (tevent_req_nterror(state->req, status)) {
 235                 return;
 236         }
 237
 238         status = cldap_socket_init(state, NULL, dest, &state->cldap);
 239         if (tevent_req_nterror(state->req, status)) {
 240                 return;
 241         }
 242
 243         TALLOC_FREE(state->netlogon);
 244         state->netlogon = talloc_zero(state, struct cldap_netlogon);
 245         if (tevent_req_nomem(state->netlogon, state->req)) {
 246                 return;
 247         }
 248
 249         if ((state->domain_name != NULL) && (strchr(state->domain_name, '.'))) {
 250                 state->netlogon->in.realm = state->domain_name;
 251         }
 252         if (state->domain_sid) {
 253                 state->netlogon->in.domain_sid = dom_sid_string(state, state->domain_sid);
 254                 if (tevent_req_nomem(state->netlogon->in.domain_sid, state->req)) {
 255                         return;
 256                 }
 257         }
 258         state->netlogon->in.acct_control = -1;
 259         state->netlogon->in.version =
 260                 NETLOGON_NT_VERSION_5 |
 261                 NETLOGON_NT_VERSION_5EX |
 262                 NETLOGON_NT_VERSION_IP;
 263         state->netlogon->in.map_response = true;
 264
 265         DEBUG(4,("finddcs: performing CLDAP query on %s\n",
 266                  state->srv_addresses[state->srv_address_index]));
 267
 268         subreq = cldap_netlogon_send(state, state->ev,
 269                                      state->cldap, state->netlogon);
 270         if (tevent_req_nomem(subreq, state->req)) {
 271                 return;
 272         }
 273
 274         tevent_req_set_callback(subreq, finddcs_cldap_netlogon_replied, state);
 275 }
 276
 277
 278 /*
 279   we have a response from a CLDAP server for a netlogon request
 280  */
 281 static void finddcs_cldap_netlogon_replied(struct tevent_req *subreq)
 282 {
 283         struct finddcs_cldap_state *state;
 284         NTSTATUS status;
 285
 286         state = tevent_req_callback_data(subreq, struct finddcs_cldap_state);
 287
 288         status = cldap_netlogon_recv(subreq, state->netlogon, state->netlogon);
 289         TALLOC_FREE(subreq);
 290         TALLOC_FREE(state->cldap);
 291         if (!NT_STATUS_IS_OK(status)) {
 292                 state->srv_address_index++;
 293                 finddcs_cldap_next_server(state);
 294                 return;
 295         }
 296         if (state->minimum_dc_flags !=
 297             (state->minimum_dc_flags & state->netlogon->out.netlogon.data.nt5_ex.server_type)) {
 298                 /* the server didn't match the minimum requirements */
 299                 DEBUG(4,("finddcs: Skipping DC %s with server_type=0x%08x - required 0x%08x\n",
 300                          state->srv_addresses[state->srv_address_index],
 301                          state->netlogon->out.netlogon.data.nt5_ex.server_type,
 302                          state->minimum_dc_flags));
 303                 state->srv_address_index++;
 304                 finddcs_cldap_next_server(state);
 305                 return;
 306         }
 307
 308         DEBUG(4,("finddcs: Found matching DC %s with server_type=0x%08x\n",
 309                  state->srv_addresses[state->srv_address_index],
 310                  state->netlogon->out.netlogon.data.nt5_ex.server_type));
 311
 312         tevent_req_done(state->req);
 313 }
 314
 315 /*
 316    handle NBT name lookup reply
 317  */
 318 static void finddcs_cldap_name_resolved(struct composite_context *ctx)
 319 {
 320         struct finddcs_cldap_state *state =
 321                 talloc_get_type(ctx->async.private_data, struct finddcs_cldap_state);
 322         const char *address;
 323         NTSTATUS status;
 324
 325         status = resolve_name_recv(ctx, state, &address);
 326         if (tevent_req_nterror(state->req, status)) {
 327                 DEBUG(2,("finddcs: No matching NBT <1c> server found\n"));
 328                 return;
 329         }
 330
 331         DEBUG(4,("finddcs: Found NBT <1c> server at %s\n", address));
 332
 333         state->srv_addresses = talloc_array(state, const char *, 2);
 334         if (tevent_req_nomem(state->srv_addresses, state->req)) {
 335                 return;
 336         }
 337         state->srv_addresses[0] = address;
 338         state->srv_addresses[1] = NULL;
 339
 340         state->srv_address_index = 0;
 341
 342         finddcs_cldap_next_server(state);
 343 }
 344
 345
 346 /*
 347  * Having got a DNS SRV answer, fire off the first CLDAP request
 348  */
 349 static void finddcs_cldap_srv_resolved(struct composite_context *ctx)
 350 {
 351         struct finddcs_cldap_state *state =
 352                 talloc_get_type(ctx->async.private_data, struct finddcs_cldap_state);
 353         NTSTATUS status;
 354         unsigned i;
 355
 356         status = resolve_name_multiple_recv(ctx, state, &state->srv_addresses);
 357         if (tevent_req_nterror(state->req, status)) {
 358                 DEBUG(2,("finddcs: Failed to find SRV record for %s\n", state->srv_name));
 359                 return;
 360         }
 361
 362         for (i=0; state->srv_addresses[i]; i++) {
 363                 DEBUG(4,("finddcs: DNS SRV response %u at '%s'\n", i, state->srv_addresses[i]));
 364         }
 365
 366         state->srv_address_index = 0;
 367
 368         finddcs_cldap_next_server(state);
 369 }
 370
 371
 372 NTSTATUS finddcs_cldap_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx, struct finddcs *io)
 373 {
 374         struct finddcs_cldap_state *state = tevent_req_data(req, struct finddcs_cldap_state);
 375         bool ok;
 376         NTSTATUS status;
 377
 378         ok = tevent_req_poll(req, state->ev);
 379         if (!ok) {
 380                 talloc_free(req);
 381                 return NT_STATUS_INTERNAL_ERROR;
 382         }
 383         status = tevent_req_simple_recv_ntstatus(req);
 384         if (NT_STATUS_IS_OK(status)) {
 385                 talloc_steal(mem_ctx, state->netlogon);
 386                 io->out.netlogon = state->netlogon->out.netlogon;
 387                 io->out.address = talloc_steal(mem_ctx, state->srv_addresses[state->srv_address_index]);
 388         }
 389         tevent_req_received(req);
 390         return status;
 391 }
 392
 393 NTSTATUS finddcs_cldap(TALLOC_CTX *mem_ctx,
 394                        struct finddcs *io,
 395                        struct resolve_context *resolve_ctx,
 396                        struct tevent_context *event_ctx)
 397 {
 398         NTSTATUS status;
 399         struct tevent_req *req = finddcs_cldap_send(mem_ctx,
 400                                                     io,
 401                                                     resolve_ctx,
 402                                                     event_ctx);
 403         status = finddcs_cldap_recv(req, mem_ctx, io);
 404         talloc_free(req);
 405         return status;
 406 }